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W. G. CUMMING.

TIRE INFLATING MECHANISM.

APPLICATION FILED JUNE 4. I917.

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a latent Specification of Letters Patent.

. application filed June l, 1917. lterial lilo llfl,ltlfl.

To all whom it may concern:

Be it lznown that l,' "Wnenian .Gronnou- CUMMING, a subject of His Majesty the King of Great Britain and llrelanch and residing at Montreal, Province ol'iQuebec, Dominion of Canada,

: flating Mechanisms, of which the following I to i v was that when the cylinder was lf'ull oil Ell ' tire tread. 'lhese is a specification.

inflating pneumaticjtires and has for its object to provide a means by whichfithe weight of the vehicle to maintain the necessary airv pressure within the tire.

When a tire becomes flattened, that IS, it is forced nearer to the run.'

Various attempts have ate tirepumps by the reciprocation oi the cylinder withan inlet valve a piston with a piston valve, apiston rod connecting the piston with the tire tread.

The intended operation of these devices air,

drawn in through the inlet valve, and the piston operated by the tread compressed that air, that it would valve into the tire. 1

lit is evident that the air in the cylinder before the stroke otthe piston would be at atmospheric pressure. within the tire would beat a. much higher pressure. Furthermore. it is evident the piston would have to travel one half the length of the c linder to raise the pressure to two atmosp eres and three quarters of the cylinder length to raise the pressure to tour atmospheres.

llt will therefore be clear that the interior pressure of the tire will keep. the piston valve closed for the greater portion of the travel of the piston.

he a result the slight change of position of the tread would have no eflect in inflating the tire and hence would not achieve the de sired result. Y By the means employed in my invention the slightest reciprocation of the tread will eflectually inflate the tire and thereby maintain the desired pressure of inflation.

Clhe device consists of a cylinder normally pass through the piston have invented certain new and useful improvements in flllre-lrr will operate a device partially deflated, that portion supporting the vehiclebecomesis used to suclr new air e v i p which air will be forced past the piston into beenmade to operdevices comprised amovement of the hereto annexed form of the means employed to carryout Whereas the air that filled with air directly connected with that in the tire and therefore at the same pressure. 'lhe piston when operated by the tread is drawn toward the rim and from the cylinder head thereby creating suction and hence draws air into the end oi. the cylinder through the inlet valve When the operatlng portion of the tread is relieved at I y the pressure oi the vehicle the piston is 'llhis invention relates to mechanism for torced to the end oi the cylinder by the pressure of the ir in the tire, increased by the tensiony or; an adjustable coil spring" within the cylinder and the air compressed in the cylinder end is forced through the piston valve and thereby increases the pres thechamber connected to the tire, by the re turn of the piston to its normal position when the weightot the vehicle has passed.

the operating portion at the ceased to'flatten that portion.

lErom this brief account of theineans employed it will a pear that the slightest piston will tend to increase the pressure within the tire, and thus main tread, and has tain a full inflation.

Reference will bernadeto the drawings in giving the details of one my invention.

, Figure l is a sectional viewthronghthe center of the plunger.

Fig. 2 is a sectional view at right angles to that of Fig. 1, through the same center.

Fig. 3 is a cross section on line'iflkiil oil l erring to the drawings it represents the tire, the inner tube, the rim and li the fell car. the inner tube is inflated is replaced by a tube 1* flanged at E and threaded enter nally. lhe flangedfend is secured to the aperture in the inner tube by the usual washer E and nut E Through the tube h] the 'ilunger ll slides freely. The plunger ll is hollow and is journalcd atits lower end to the button or base J by the pin J through the journals J it flat headed screw (l passes through the inner tube ll and enters the bottom of the button ll of an ordinary wheel oil a motor Tie usual valve tube through Which fill llii

A packing washer E and nut E bear di- D and secure the v at the proper adjustment.

' tions P forms a chamber R which is filled upper part of the cylinder The cylinder G is closed at its upper end into which an ordinary tire valve S is screwed-and by means of which the inner tube may be inflated by the usual means or the air pressure within the tire tested.

The pump cylinder M is adjacent to the cylinder G, and is cast integral with it. The cylinders are connected by the slotted aperture M I i The lever L is journaled in the slot M by pin L The cylinder head 0 of the cylinder M has an inlet valve A cap P with perforawith suitable material to filter the air passing through the valve The piston N. is rovided with suitable packing disks or rings and has an inlet valve N The piston rod N? is hollow and is perforated at N. The lower end of the rod N is slotted at N"- to receive-thexendof the lever L. 3] 1 A cap N screwsoverthe lower end of the rod N Through this cap'N't anadjustment screw N passes whereby the hardened steel bar N can be readily adjusted.

The lower end of the cylinder M is' closed the threaded plug M and a coil spring 1 between this plugv andthe cap N forces the piston N normally against the cylinder head 0. The tension of the spring N can be adjusted by'the position of the plug M The plunger is preferably flattened to present a straight edge to the lever L. l 1

The lever L is journaled so that it lowers the piston on limited movements of the plunger, but in the event of an extended thrust of the plunger as the result of a blow :out

or a violent jar, the end ofthe' lever retires asses into the When the into the slot and the plunger plunger H returns to its normal position the lever follows it being forced out of the slot by the spring N p 1 From the foregoing description'it will appear that at each'revolution of the wheel if the tireflattens the plunger will rise, thereby lowering the piston and in so doing will draw air in through the inlet valve 0 into the end of the cylinder M.

As the tire resumes its proper curvature the plunger is lowered and the piston is forced upward by pressure of the air in the inner tube increased by the tension of the spring, and the air that was in the end of the cylinder M- will pass through the inletvalve N of the piston and increase the pressure in the inner tube.

By this means a small quantity of air will be brought in whenever the tire becomes at all flattened, while a violent movement of the tire surface will not injure the device or put it out of action.

Having now described my invention what I claim is; v

1. In a device of the class described, the combination of a plunger cylinder, a plunger secured at one end to the tread of a tire, a suction pump ad acent to the plunger c v1.

inder, comprlsmga cylinder with a valve in the cylinder head leading from an air supply, a piston normally in contact with the cylinder head, with a valve therein leading to a passage to the interior of the tire, a

lever pivoted in a slot between the cylinders, and a spring bearing on the piston as described.

2. In a device of the class described the combination of a suction pump having the piston normally in contact with the cylinder head and valves in both the piston and the cylinder head between which there is no air space and means to reciprocate the piston thereof.

3. Ina device of the class described the combination of a suction pump having the piston normally in contact with the cylinder head and valves in both the piston and the cylinder head between which there is no air space, an air supply passage thereto, a pas-. sage therefrom to the interlor of the tire and means to reciprocate the piston thereof by thefiattening and rebound of a portion of the tire tread.

4. In a device of the class described, the combination of a suction pump, comprising a cylinder, a piston normally in contact with the cylinder head and valves connecting with an air supply and with the interior of the tire, and means to reciprocate the piston by the flattening and rebound of a portion of the tire tread.

5. In a device of the class described, the combination of a suction pump having the piston normally in contact with the cylinder head and valves in both the piston and the cylinder head between .which there is no air I spaceyan air passage leading thereto, a filter in said passage. a passage therefrom to the interior of the tire, and means to operate the pump by the flattening of a portion of the tire tread and by the tension of a spring.

6. In a device of the class specified the combination of means to actuate a suction pump by the limited flattening of a portion of the tire tread and a suction pump comprising a cylinder, a piston normally in contact with the cylinder head, a valve in the cylinder head from a passage connecting with the outer air, and a valve in the piston leading to the interior of the tire as de scribed.

7. In a device of the class specified the tetaora tit combination of a cylinder connected with the interior of a tire, an inlet valve in the cylinder heath a piston normally incontact With the cylinder head, an inlet valve in the piston, and means attached to the tire tread adapted to Withdraw the piston by the flattening of the tire, and means to return piston When the flattening of that portion ceases. I 8. In a device of the class specified the combination of a cylinder provided with an inlet valve in the eylinder head; a piston normally in contact with eylinclerheatl an inlet valve in piston, means to draw piston l "l lllilillrtllll GUlttDUhl' tllllt/lll/tll lfir, 

